Earth Science Club of Northern Illinois - ESCONI

Trace Elements Play Part in New Theory on Crust Formation

Via PhysOrg:

... The oceanic crust did not have to descend

Using computers, the scientists simulated the composition of bedrock and molten rock that would emerge from partially melting the oceanic crust at various depths and temperatures. They then compared the data calculated for the molten rock with the actual concentration of trace elements in the oldest continental rocks. "Our results paint a surprising picture," Dr. Nagel reports. "The oceanic crust did not have to descend to a depth of 100 kilometers to create the molten rock that makes up the rocks of the first continents." According to the calculations, a depth of 30 to 40 kilometers is much more probable.

The primeval oceanic crust could have 'oozed' continents

...it could definitely have had the power to do so in the Archean eon.... More

 

Please Return Rocks and Only Take As Many As You Need

Via The Onion:

A coalition of geologists are challenging the way we look at global stone reserves, claiming that, unless smarter methods of preservation are developed, mankind will eventually run out of rocks.

"If we do not stop using them up at our current rate, rocks as we know them will be a thing of the past," renowned geologist Henry Kaiser said at a press conference Tuesday. "Igneous, metamorphic, even sedimentary: all of them could be gone in as little as 500,000 years."...

Geologist Victoria Merrill, who has been at the forefront of the rock conservation battle since 2004, said there are simple steps people can take to reduce their rock consumption.

"Only take as many rocks as you absolutely need," said Dr. Merrill, author of the book No Stone Unturned: Methods For Modern Rock Conservation. "And once you are finished with your rocks, do not simply huck them into the woods. Place the rock down gently where you found it so that others may look at the rock and enjoy it for years to come."... more

Image: USGS